Donald Trump has attacked China on Twitter yet again. Just days after he committed a serious breach of diplomatic protocol by phoning Taiwanese President Tsai Ing-wen, Trump used his Twitter account to criticize China in stark terms. His ability to irritate China has many experts worried.

“Did China ask us if it was OK to devalue their currency (making it hard for our companies to compete), heavily tax our products going into their country (the US doesn’t tax them) or to build a massive military complex in the middle of the South China Sea?” Trump said on Twitter. “I don’t think so!”

Trump’s latest attack on China comes as his team is trying to do damage control for his 10 minute conversation with the Taiwanese president. China considers Taiwan a rebellious province and the United States has always been careful in dealing with Taiwan. Trump’s decision to talk directly to the Taiwanese leader enraged the Chinese.

The presidential transition team has defended Trump’s phone call and praised President Tsai as ‘democratically elected’. This attitude will only further worry Chinese leaders as Trump attacks their trade and military policy. The US has longstanding concerns about Chinese trade practices and aggression in the South China Sea but previous administrations have taken a measured approach.

Trump’s claim that China should ‘ask us’ if it was permissible to devalue its own currency goes far beyond normal US-China relations. The US has no power to tell China how to behave and the Chinese government reacts poorly when it is treated like an inferior. China has no intention of asking America’s permission for anything.

The Twitter attack on Beijing’s policies may not signal a key change in US policy towards China but Trump’s consistent criticism of China and his team’s defense of the diplomatic faux pas with Taiwan has already altered US-China relations. Donald Trump’s tweets have often dominated the news cycle but they now appear to be changing America’s position in the world.